Noncorrodible reenforced pipe



Patented June 10,V 193() orHo v. KEAN, or PROVIDENCE, RHODE ISLAND NoNcoRRoDIDLE RDENFORCED :PIPE

Application mea 4January 22, 1927. serial No. 162,756.

This invention relates to improvementsin reenforced pipe construction adapted for general application such, for example, as in Amunicipal water distribution systems, in pipe 5 lines for transporting gas or oil, and for like uses. More particularly, in some of its'details, the invention relates to improvements inthe reenforcement of pipes ofl metal or other material by means of a reenforcing casing or envelope.

It is a general object ofthe invention to provide an improved pipe construction which is specially strong, while being light and in'- expensive in production costs.

vide an improved pipe of the class mentioned, having high corrosion resisting qualities, while .being exceptionally strong so as to adapt it for uses under comparatively high internal pressures heretofore unavailable for the corrosionresisting type of pipe.

A further' objectof the invention is to provide an improved reenforceinent for pipes of resisting cast iron or similar material of high corrosion qualities, so as to adapt the pipe for luses under relatively high internal pressure,

l and to adapt it for uses where exposed t0 damage by external agencies tending to crush, bend, or otherwise' damage the pipe. l A further object of the invention is to provide an improved reenforced pipe of high corrosion resistivity while limiting to a minimum amount rthe degreecontraction under variations of internal pressure.

y effectively excluded from contact with the -b Still another-object is to provide animproved reenforced pipe construction whereby corroding agencies, such as moisture, are

0 walls ofthe pipe.

5 compression,

than by the A further object of the invention is to provide an improved reenforcement for metallic, clay, the wall of the pipe is placed und'ei initial absorbed directly by the reenforcement rather walls of the pipe. Still another .object of the invention is to 0 provide an improved reenforcement for pipes A further object of the invention is to proof expansion andv cement, or other pipes wherebyand wherein the s'tressesdue to normal service pressures within the pipe are' so as to limit the expansion and contraction thereof under service pressures, and thus to min imize the tendency of` the=pipe to part or separate,eith'er at the outside or inside surfaces thereof, from any protective linings or reenforcing coatings or casings such,-for example,

as cement or reenforced concrete.

A further object of the invention is to provide an pipes so ing, cracking, such pipes.

improved reenforcement for chilled' as to minimize the danger of break- Another object is to providean improved reenforcement for stift' resistance n pipes or the like so-asto pipe longitudinally and increase its to bending stresses.

en the A further object of the invention is to provide an improved fastening device for securing a'plpe or tube which ing Vhe ends of reenforcing wires or bands to is reenforced by windthe wire orband therearound.

Another object of the invention is to provide animproved reenforcing casing-0r -en velope for pipes or the like, which is made of corrosion resisting material such, for examas stainless steel or similarl non-corrodible metal.

A further object of the invention is to provide a protective wrapping or like covering,

for pipes, including a burl lacq ing fabric suchV as cloth or ap impregnated with bakelite varnish or uer, so as vto effectively exclude corrodagencies from access to the surface of the pipe, or to the outer reenforcing envelope thereof. i

O nect tion ther objects will be in part obvious in conionwith the following detailed descripof certain illustrated but preferred emodiment of the invention and will be in part pointed out therein. y y

For amore complete understanding of the nature 4and objects of the invention, reference is had to the following detailed description of the illustrative embodiment,- and to the accompanying drawings, in which longitudinal section of a bodyingthe invention.

ig. 1 is a sideelevation partially in central Fig. 2 is a transverse section thereof.

igs. 3, 4, and 5, are enlarged'cross secor other rupture or damage in pipe or tube em-w 4tional views vof different forms of wire. or

` Wal-ls.

i ent materials.

band used in the pipe reenforcement.

Fig. 6 is a view similar to Fig. 1, but showin a modified form of the reenforcing en- ;ve ope or casing.

Fig. 7 an enlarged cross sectional view of the reenfforcing band or strip of Fig. 6.

Fi s'. 8 and 9 are respectively cross sectiona and 'side elevational views of a further embodiment of the invention.

Fig. 10 is a cross vsectional vie'w slmilar to F lgs. 2 and 8, but showing the reenforeing pipe constructlon embedded in" cement or concrete, and

Fig. 11 is an elevation showing a further modified-form of the reenforc'ng envelope. v Referring to the drawing for a detailed description of the illustrative embodiments of vthe invention there shown, and .first to the embodiment shown in Figs. 1 and 2, a pipe or tube 15 is provided having imperforate This tube ma be made in various lengths, diameters anl wall thicknesses,de pendent .upon the service in which it is to be employed, and it may also be made of differ- Steel has an advantage in strength, or in lightness for a given strength,

but it is disadvantageous fromthe. stand-l point of production costs, and it is also more susceptible to influences of rustv and corrod'. lng agents, 1n various. uses both below and.

above ground, thanare certain other materials such,`for example, as cast iron, clay, or cement. j o

In order to reenforce the tube 15, an enclosing casing or envelope is provided indicated generally at 16. This reenforcing casing is preferably madeof a band Wrapped around the outside of the lpipe in the form of a c oi1,tl 1e ends and intermediate parts of which ma be suitably secured to the pipe. This reen orcing coil or envelope prefera ly extends throughout the longitudinal extent of the pipe, that is, from end to end ofthe reenforced pipe sections. The reenforcing band may take the form of a wire 17, circular in section, as shownin Figs. 1, 3 and 4, or ,it may be of other sectional shapes, some yof whlch are illustrated in Figs. 5, 6,7 and 11. i

Thereenforcing casing is of a material` having considerably greater tensile strength,

l greater elastic limit under tension, and 'great- .er modulus of elasticity undertension, than the/same characteristics of the material form! ing the innerA pipe part or tube 15'. For

vmany purposes avery advantageouscombi-` nation for'the construction of the composite reenforcing pipe, is where the inner tube part 15 is made of cast iron and the reenforced casingor envelope is' madeof steel of high tensile, strength. Under these conditions advantage is taken of the high resistance to 'corrodinginfluences of the cast iron, both at Vthe outer and inner surfaces thereof, and of the-relatively greatstrength afforded by the :steel reenforcing envelope.v By means of4 this combination it is possible to construct a pipe which is light compared with cast iron construction while -having lthe' requisite strength for installation in water distributing systems, pipe lines for'transporting oil or gas, and like uses. Moreover,'this con-` struction attains such other' advantageous -This feature will no'w be disclosed.

The band or wire 17 :is Wound upon the inner tube 15 lunder considerablev ftension so asto place the walls of said tube under heavy compression, which may,in` certain cases, reach a value approximating 10,000 .pounds per square inch, but thedegree of compres` sion may vary with the pressure to be carried within the pipe.4 The initial stress of 'comression imposed by the reenforcing enveope upon the walls ofthe inner tube 15 is preferably higher per unit area than the stress per unit area which would be'imposed upon the pipe walls by"normal internal serv.

icepressures carried by the ipe. The effect of this relation is that the tu e walls areconstantly maintained under compressive stress by Vthe action of the reenforcing envelope during normal erviceoperation of the pipe. i The result is that the load of the internalv pipevpressure is carried by the reenforcing envelope, which is appropriately designed for this purpose, While the inner tubular part 15 vprovides the principal part of the requi-l site plpe rigidity, resistance to external crushing forces andV to bending stresses,

while also resisting tendency to rust or cor- Y rode, as mentioned above.

Duev to the greatt'en'sile strength of the reenforcing envelope, as compared with that of the material of tube 15, it will be seen that the Walls of said tube may 'be constructed relatively thin. Also by virtueof the higher I modulus of elasticity undertension of the reenforcing envelope, as compared with that of the in ner ltube 15, the radialexpansion or contraction of the composite pipe, under variation of internalpressures', w1ll be greatly reduced over values where the pipe is constructed of .a material having" a lower modalus of elasticity than that of the reenforcing casing.- It will be noted that the stripor AWire of the vreenforcin'g casing may be off hardened steel of great tensile strength and having high 'modulus of elasticity. lThis l vfeature is of great A importance in cases where 'the pipe `1s embodled 1n a reenforclng cover- 4 lng such, for example, as the concrete block contraction under' variations ticity ofthe pipe and concrete. This parting results in a crack or space between the `plpe and concrete, permitting access of mois-A .ture and other corroding agents tending to tion above set forth.

hasten pipe rust and corrosion'. This tendency is materially reduced by the vconstruc- It will be .understood that in the embodi- I ment shown 1n Fig. 10 the concrete or cement the Wall thereof.

embedded pipe is constructed as above described,'with the Walls` of the inner tube'15 under compression imposed by the reenforcingpenvelope 16. Also, as shown in this ligure, a cement lining 19 may be' placed on 4the inner Walls of the pipe for protection thereof, and the parting or separation of this lining from the walls of the pipe; under influences as suggested above is considerably reduced for reasons mentioned. i

The ends of the reenforcing Wire may be attached to the tubing 15 by means of a hole 20 drilled into the pipe for'the receptionof the bent end 21 of the wire. e This hole may be positioned `in the transverse face of the pipe end, or it may be formed in the outer tubular face of the pipe, extending transveresly of This connection binds the wire and holds it during application of tension when the reenforcing'casing is being placed in position, and helps to hold the casing 1n thereof. Also the reenforcing bands of wires may be attached to the outer surface of the tube 15 at various points therealong as by 'welding or soldering, but preferably by brazing. These brazed attachments may be spacedas desired along the tube, or they may be in a substantially continuous linewhereby each convolution of thereenforcing casing is secured to the tube 15.

The pipe is shown with a bell or enlar ement 22 for lthe reception oi.` the end o? a' companion pipe in ,connected relation. It will be observe'dthat the reenforcing envelope is continued over stantially to the end of the pipe, thus pro'- viding a reenforcement for this part of the pipe and prot'ectin it against breakage. This reenforcement 1s geou's, since the connections between adjacent pipe sections are frequently subjected to ex- 4 ceptional stresses.-

f ....Inzgorder to velope from -corroding influences, the reenforcing band, Whetherl of circular section VWith balelite varnish or bakelite vterial.

position after complete application this enlargement subparticularly advan ta-.4v

protect the reenforcing-"en- '27, but in this still further protectingl the pipe from cor-l roding influences, a protective Wrapping or coating 23 may be Wrapped or the corrosion resistant material used. As shown in Figs. 8 and 9, this protective coating is in the form of thoroughly dried burlap or similar fabric, impregnated laquer composition. This impregnated 'burlap is preferably in the form of a long spirally upon the outer surface of the pipe with' theadjacent edges of the strips arranged in overlapping relation.

As shown in Figs. 8 andl 9,'thetensioned reenforcing envelope may lbeapplied to a 'chilled tube or pipe 24, similar inform to the tube 15, but having an outer zone of the meta-l iva/ll` thereof chilled as indicated at 25, forming an outer -hardened annular zone of metal which is normally under tension so asto impose a compressive force upon the inner annular zone of the pipe. This chilled tube may beef cast iro steel, or otherma- When the reeforcing envelope vis placed in position upo this chilled pipe a tension'is applied suiiicient to overcome the initial tension of the chilled zone andplace the tube Wall under compression throughout its entire thickness. This construction 1n addition' to the advantages already pointed tout inthe foregoing disclosure, relieves the tube of stresses Within the chilled zone, thus decreasing the tendency to crack or break or to fail otherwise. The reenforcing envelope in this and other forms of the inven- Vtion functions as a cushion tok protect .thev

pipe from damage due to external blows or pressure.` .I c v In` the form of the inventlon shown 1n Fig. v1l, the reenforcing band is in the form of a fiat metallic stripl 26 Wound in two superposed la ers, both of which may be tensioned as a ove described. The convolutions of the overla the adjoining edges of the convolutions irectly therebeneath: inother words,

placed over the outer surface of the pipe, whether or'not the pipe is strip -Wound outer layers are arranged tol materialsuch, for v Thls corrosion the flattened or rectangular strip forming `1 an outer convolution breaks.V joints with twov underlying convolutions.

casejthe reenforcing band vis In this manner,

the convolutions of the reenforcing envelo ev provided Avi'rith flanges orf-formations'28 29 at .diagonally opposite corners thereof, thus providing a strip substantially' Zf shaped in section. This 'construction pro'- vides mating or complementary interengaging formations V'for the adjacent edges of ad]acent convolutions. This Vstrip may be' Wound under tension as'above described, the

adjacent edges of the strip interfengaging.

or inter-locking so as to substantially reenforce and rigidify the pipe against longitudinal bending stresses.

The ree'nforcing band for the envelope. may be substantially square insect-ion, as indicated vat 30 in Fig. 5, and in any sectional form the band may be covered with a protective jacket or layer 31 of corrosion resisting material toprotect the band from corrosion agents.

Since-certain changes may be made in'the above constructionv and different embodiments .of the .invention could be made without departing from the scope thereof, vitis intended that all matter contained in the ferential compression and an outer reenforce-A i vbed in which the ipe is embedded and which pipe.

above description or shown in the accom-j panying drawing -shall be interpreted as illustrative and not in a limiting sense.

zone and a reenforcing enve ope stressed -to l 5. A cast metal ha i a. chilled outer l placev said chilledjzone under circumferentialcompression.

In testimony whereof I aix my si turei m VOTHo v. AN.

It isalso to be lunderstood that the folf 'lowing claims'are 'intended .to coverjall of the generic and speciic features of the in'-l ter of language, might be said to fall there#- l Patent is:

msf4

'1. A cast'iron pipe having a chilled outer 'A zone and a tensioned reenforcing winding of steel band therearound. "2; A'cast iron pipe havin achilled outer zone and a reenforcing windingof steel band therearound, said reenforcing' 'winding being under such tension as to maintain the wallsof the pipe including said chilled outer .zone under circumferential compression under` normalinternal pressure carriedby thepipe. Y

QB. In combination, a cast iron pipe-having la'cliilled outer zone, a reenforcing Winding ofsteel band around said pipe and being tensioned` to place the pipe walls in circummen-t of cement or the likev in .the form of'a is in contact the outer surface of the 4. In combination, a cast iron `pipe having a. chilled outer zone, a reenforcing winding l ofsteel bandfthereaound,'said reenforcing winding being under such'tension as to maintain the walls of the pipe under circumfereni tial compression under normal internal pressure carried by the pipe, and an vouter reenforcement of cement orthe like in vcontact l i s with the outer Surface ofthe pipe; 

